Biorhythmologic aspects of seizure activity

Seasonal and circadian rhythms of neuronal and organism resistance to convulsive effect of strychnine and penicillin were studied in vivo on mice and rats and in vitro on cultured mouse cerebellar sections. Resistance was assessed by the latency of seizures in mice and neuronal response to convulsants in sections. In the night and morning time (0:00-9:00) seizure resistance in mice increased: it manifested in longer latency and lower mortality compared to those in the day and evening time (12:00-21:00). Seizure resistance was minimum in autumn and maximum in winter. Neurons in cerebellar section were most resistant to the convulsive effect of penicillin in autumn and winter and least resistant in spring and summer. Circadian rhythms of cerebellar neuron resistance to convulsants were opposite, which attests to reciprocal relations between epileptogenic and antiepileptic (cerebellar) cerebral structures.